Study Design. Concurrent, prospective, randomized, and observational cohort study. Objective. To assess the 4-year outcomes of surgery versus nonoperative care. Summary of Background Data. Although randomized trials have demonstrated small short-term differences in favor of surgery, long-term outcomes comparing surgical to nonoperative treatment remain controversial. Methods. Surgical candidates with imaging-confirmed lumbar intervertebral disc herniation meeting SPORT eligibility criteria enrolled into prospective, randomized (501 participants), and observational cohorts (743 participants) at 13 spine clinics in 11 US states. Interventions were standard open discectomy versus usual nonoperative care. Main outcome measures were changes from baseline in the SF-36 Bodily Pain (BP) and Physical Function (PF) scales and the modified Oswestry Disability Index (ODI -AAOS/Modems version) assessed at 6 weeks, 3 months, 6 months, and annually thereafter. Results. Nonadherence to treatment assignment caused the intent-to-treat analyses to underestimate the treatment effects. In the 4-year combined as-treated analysis, those receiving surgery demonstrated significantly greater improvement in all the primary outcome measures (mean change surgery vs. nonoperative; treatment effect; 95% CI): BP (45.6 vs. 30.7; 15.0; 11.8 to 18.1), PF (44.6 vs. 29.7; 14.9; 12.0 to 17.8) and ODI (Ϫ38.1 vs. Ϫ24.9; Ϫ13.2; Ϫ15.6 to Ϫ10.9). The percent working was similar between the surgery and nonoperative groups, 84.4% versus 78.4% respectively. Conclusion. In a combined as-treated analysis at 4 years, patients who underwent surgery for a lumbar disc herniation achieved greater improvement than nonoperatively treated patients in all primary and secondary outcomes except work status. Key words: SPORT, intervertebral disc herniation, surgery, nonoperative care, outcomes. Spine 2008;33:2789-2800 Lumbar disc surgery remains one of the most commonly performed operations, with rates exhibiting considerable geographic variation. 1 Two recent randomized trials demonstrated that surgery provides faster pain relief and perceived recovery in patients with herniated disc. 2-4 Outcomes were similar at 1 year for patients assigned to surgery and for those assigned to nonoperative treatment. However, both trials included substantial numbers of surgical patients in the nonoperative comparison arm due to treatment crossover, affecting the interpretation of the intent-to-treat analyses. This paper reports 4-year results for SPORT based on the continued follow-up of the herniated disc randomized and observational cohorts. Materials and Methods Study Design SPORT was conducted in 11 US states at 13 medical centers with multidisciplinary spine practices. The human subjects committees at each participating institution approved a standardized protocol for both the observational and the randomized cohorts. Patient inclusion and exclusion criteria, study interventions, outcome measures, and follow-up procedures have been reported previously. 3-5 Patient Population Men and women who had symptoms and confirmatory signs of lumbar radiculopathy that persisted for at least 6 weeks, who had disc herniation at a corresponding level and side on imaging, and who were considered surgical candidates were eligible. The content of pre-enrollment nonoperative care was not prespecified in the protocol. 3-5 Specific enrollment and exclusion criteria are reported elsewhere
